POS1084 EFFECT OF RHEUMATOID ARTHRITIS ON TOTAL KNEE ARTHROPLASTY
Authors: W. Jeong, J. Kim
Journal: Annals of the Rheumatic Diseases (2023)

<h3>Background</h3> According to the results of previous studies, it has been reported that rheumatoid arthritis (RA) patients receive total knee arthroplasty (TKA) at a younger age than osteoarthritis (OA) patients. However, studies on the effect of RA on TKA are still insufficient. <h3>Objectives</h3> We conducted this study to find out how RA affects primary TKA and revision arthroplasty. <h3>Methods</h3> The data of OA and RA patients who underwent primary TKA and revision at Jeju National University Hospital between March 2003 and December 2022 were retrospectively analyzed. To exclude the effect of other connective tissue diseases, patients with SLE, Sjogren's syndrome, polymyalgia rheumatica, mixed connective tissue disease, undifferentiated connective tissue disease, Behcet's disease, systemic sclerosis, and vasculitis were excluded. <h3>Results</h3> A total of 5245 TKAs were performed, and the average age at primary TKA was 72.4 ± 6.4 years, and 2292 (85.7%) were female. When they were divided into OA group and RA group, RA knees were 159 (3.1%). The age at primary TKA in the RA group was significantly smaller (69.6 ± 6.8 vs 72.5 ± 6.4, p&lt;0.001), and the female ratio was higher (91.9% vs 85.5%, P=0.031). Although the rate of revision surgery was not statistically significant, the RA group had more (5.6% vs 3.1%, p=0.111), and the period to revision tended to be shorter in the RA group (33.8 ± 49.2 months vs 67.7 ± 56.1 months). month, p=0.078). The cause of reoperation was not significantly different between the two groups, but the rate of infection was higher in the RA group (55.6% vs 43.7), and reoperation due to loosening was more common in the OA group (46.2% vs 22.2%). There was no difference in other test values at the time of surgery, but in the RA group, ESR (43.8 ± 31.7 mm/h vs. 26.6 ± 22.6 mm/h, P&lt;0.001), CRP (1.8 ± 2.3 mg/dL vs. 0.8 ± 2.1 mg/dL, p&lt;0.001) was significantly higher. The incidence of TKA was higher in the RA patients than OA patients (1436.2 per 100,000 Person-Years vs 1379.7 per 100,000 Person-Years). When comparing the risk of patients undergoing primary TKA during their lifetime by adjusting for gender, it was found that RA patients started receiving primary TKA at a younger age and had a significantly higher risk of undergoing TKA (HR 1.48, 95% CI 1.263–1.733, P&lt;0.001). As a result of logistic regression analysis, the increase in ESR (OR 10.2, 95% CI 1.01-1.03, P=0.001) and CRP (OR 1.09, 95% CI 1.01-1.17, P=0.021) at the time of primary TKA increase risk of revision arthroplasty, but RA did not. <h3>Conclusion</h3> Patients with RA have a higher risk of primary TKA and start primary TKA at a younger age, and the increased inflammation level at the time of primary TKA increase risk of revision arthroplasty, so it is recommended to perform primary TKA after inflammation is controlled. <h3>References</h3> [1] Ranawat CS, Padgett DE, Ohashi Y: <b>Total knee arthroplasty for patients younger than 55 years</b>. <i>Clinical orthopaedics and related research</i> 1989(248):27-33. [2] Dalury DF, Ewald FC, Christie MJ, Scott RD: <b>Total knee arthroplasty in a group of patients less than 45 years of age</b>. <i>The Journal of arthroplasty</i> 1995, <b>10</b>(5):598-602. <h3>Acknowledgements:</h3> NIL. <h3>Disclosure of Interests</h3> None Declared.